Initial design for background compilation

runtime/vm/thread_registry.cc

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/thread_registry.h"
 
+#include "vm/compiler.h"
 #include "vm/isolate.h"
 #include "vm/lockers.h"
 
 namespace dart {
 
 ThreadRegistry::~ThreadRegistry() {
   ReclaimTimelineBlocks();
   // Delete monitor.
   delete monitor_;
 }
@@ skipping 13 matching lines @@
   remaining_ = CountScheduledLocked();
   Isolate* isolate = Isolate::Current();
   // We only expect this method to be called from within the isolate itself.
   ASSERT(isolate->thread_registry() == this);
   // TODO(koda): Rename Thread::PrepareForGC and call it here?
   --remaining_;  // Exclude this thread from the count.
   // Ensure the main mutator will reach a safepoint (could be running Dart).
   if (!isolate->MutatorThreadIsCurrentThread()) {
     isolate->ScheduleInterrupts(Isolate::kVMInterrupt);
   }
+  if (isolate->compile_optimized_task() != NULL) {
+    // Make sure the task moves from Wait to a safepoint.

[koda, 2015/10/01 22:27:02]

This should not be needed anymore, now that you enter/exit the isolate in the
loop. I.e., while it's Waiting, the compilation task is not in this isolate, so
will not be included in the rendezvous.

[srdjan, 2015/10/01 23:11:24]

Done.

+    MonitorLocker ml_comp(isolate->compile_optimized_task()->monitor());
+    ml_comp.Notify();
+  }
   while (remaining_ > 0) {
     ml.Wait(Monitor::kNoTimeout);
   }
 }
 
 
 void ThreadRegistry::ResumeAllThreads() {
   MonitorLocker ml(monitor_);
   ASSERT(in_rendezvous_);
   in_rendezvous_ = false;
@@ skipping 143 matching lines @@
   for (int i = 0; i < entries_.length(); ++i) {
     const Entry& entry = entries_[i];
     if (entry.scheduled) {
       ++count;
     }
   }
   return count;
 }
 
 }  // namespace dart